Check lists allow multiple options to be selected from a permanently displayed horizontal list. A check list is created with a call to the function
void *tw_check(char *name,...)such as
tw_check(name, func, mask, name_1, name_2, ... , NULL); char *name, *name_1, ..., *name_k; void (*func)(); int mask;
Changing the checked entries sets a bit-mask mask (the lowest order bit represents choice of the leftmost item) and func is called with this as argument. The initial state of mask sets the display appropriately (remember to make this correspond to the initial state of the application).